## 25 terms

### Vertical angle

a pair of opposite congruent angles formed by intersecting lines

### Complementary angles

Two angles whose sum is 90 degrees

### Supplementary angles

Two angles whose sum is 180 degrees

### Perpendicular lines

Two lines that intersect to form right angles

### Parallel lines

lines in a plane that never intersect

### Transversal

A line that intersects two or more lines.

### Interior angle lines and angles

inside parallel lines cut by tranversel

### Exterior angles

angles on the outside of parallel lines cut by a transversal

### Alternate interior angles

angles between 2 lines and on opposite sides of a transversal

### Alternate exterior angle

two exterior angles on opposite sides of the transversal that have the same measure

### Corresponding angles

angles in the same place on different lines

### Congruent polygons

polygons with congruent angles and congruent sides

### Interior Angles polygons

an angle on the inside of a polygon formed by the sides of the polygon

### Equilateral

all sides are congruent

### Equiangular

all angles are congruent

### Regular polygon

a polygon with congruent sides and angles

### Line symmetry

if a figure can be folded over a line so that one half of the figure matches the other half

### Line of symmetry

the line that the figure is folded over

### Rotational symmetry

if the figure can be rotated less than 360 about its canter so that the figure looks exactly the same in its original position

### Angle of symmetry

the degrees measure of the angle that the figure is rotated.

### Reflection

The mirror image created by flipping a figure over a line

### Line of reflection

The line that the mirror image is flipped over

### Transformation

A technique of mapping geometric figures. For example reflecting a figure

### Image

The position the figure is in after a transformation

### Translation

The moving of a figure from one place to another without turning it